Trouble analysis and elimination of common instruments of water quality detector

Shipping problems:

(1) Sampling fault-low pressure; short sampling time; loop fault; bad sampling valve.

(2) Reagent leakage-aging of the pipeline; two three-way valves cracked.

(3) Reagents cannot enter actively-the photocoupler is out of control or check whether the photocoupler and the coupling base are well connected; check the photocoupler circuit.

(4) The peristaltic pump does not collect water-the motor drive voltage is not enough, the driver fails or the hose is deformed and aging.

Other problems:

(1) Incomplete action-debris blocking or blocking the valve core; circuit failure.

(2) The temperature of the crusher is too high or too low-the platinum resistance is damaged; the temperature controller is damaged; the heating device is damaged.

(3) The AD value is the too low or abnormal-the photometer power supply is faulty; the adjustable resistance is not well adjusted; the light-emitting diode is damaged or aging; the photodiode is damaged; the AD module is damaged.

(4) Ultra-high zero-point voltage-light gate control fails; the zero-point drift of the photometer is large.

(5) No flow-no current and voltage of the flow probe; the flow probe should have current and voltage but no signal voltage; the data interface is not well connected; the AD module is damaged (no AD signal).

Ammonia nitrogen online monitor (gas-sensing electrode method):

(1) High measured value-inaccurate or invalid calibration fluid; air-permeable membrane with bubbles; dirty air-permeable membrane; electrode failure; aging or damage of the air-permeable membrane.

(2) Low measurement value-inaccurate or invalid calibration solution; lack of reagent; slow electrode response; pollution of air-permeable membrane; electrode failure; aging of the air-permeable membrane.

(3) Calibration is invalid-the calibration fluid is not accurate or invalid; the calibration fluid is lacking; the electrode responds slowly; the air-permeable membrane is fouled; the electrode is invalid; the air-permeable membrane is aging.

(4) The pool temperature is abnormal and the temperature sensor is faulty, and the ambient temperature exceeds the ambient temperature scale required by the instrument.